This invention relates to laser diodes. More particularly, this invention relates to vertical cavity surface emitting laser diodes that are electrically injected and emit in the visible region of the spectrum.
Vertical cavity surface emitting laser (VCSEL) diodes are very useful structures that can replace LED's and HeNe lasers (at visible wavelengths) in a variety of applications. Most of the development has been in the GaAs/AlGaAs system and has been limited to infrared and deep red wavelengths. The shortest wavelength achieved has been 699 nm with this system. It would be very desirable to have a VCSEL that would provide useful output in the rest of the visible spectrum. A red emitting VSCEL structure has been reported by using the InGaP/InAlGaP system as a strained quantum well (SQW) active region, R. P. Schneider, R. P. Bryan, J. A. Lott, and G. R. Olbright, "Visible (657 nm) InGaP/InAlGaP strained quantum well vertical-cavity surface-emitting laser," Applied Physics Letters, Vol 60, No 15, Apr. 13, 1992. However, this device was optically pumped, and an electrically injected device is still an unmet need.